Imho, he was just some angry kid that got a toy and then got angrier. Shallow character development with little motivation, no surprising twists and died leaving a bunch of loose ends (Sylvanas or Mal'Ganis didn't get their revenge, Jaina didn't get to confront him, Muradin or Saurfang didn't get to see him after all that Lootship nonsense etc).

Its a snowball's chance in Hell any of these guys would resign themselves to a Video Game based movie, but...

Chris Helmsworth. (AKA Thor)

While its true Arthas began as a bland heroic and out-to-prove-himself "Once a future King" Paladin. Even had a male role model that was twice as "Wholesome" as he was. He was also cocky, arrogant and liked to take matters into his own hands. That my friends is the same character bio as the Thor from the Marvel movie.

Now picture a character like Thor in Stratholme watching families be burned alive locked inside their homes never knowing what they did to deserve it. Imagine his face twisted with rage toward Mal'ganis for making him do this to his people and the look of betrayal on their faces for their knight in shining armor commiting mass murder. Now picture Thor fully taken by Obsession, Hate, and disregard for any of his failed lessons of nobility, honor and loyalty standing above his loving father Terenas right before he "succeeded" him.

The rise and fall from hero to villian needs a character like Chris Helmsworth to give a powerful performance from the good Arthas to the Lich King. If he's good enough to Wield Mjolnir he good enough to wield Frostmourne.

They can either go and show the whole WARCRAFT Universe in few parts ( Trilogy) and show us all that wow has to offer till now or they could just concentrate on one person and narrates the story of this young prince
Personally i'd love to watch Arthas's story and see how connected it is to Warcraft universe but hey that's a long shot , in fact , lots of people would love to see Illidan and that war of the ancient thing
Good thing Arthas had some business with Illidan so no matter the outcome, we may get to see Arthas ^^

Imho, he was just some angry kid that got a toy and then got angrier. Shallow character development with little motivation, no surprising twists and died leaving a bunch of loose ends (Sylvanas or Mal'Ganis didn't get their revenge, Jaina didn't get to confront him, Muradin or Saurfang didn't get to see him after all that Lootship nonsense etc).

I honestly hope the movie isn't about him.

And this is like, your opinion, dude. I personally like a story with loose ends. I have this thing called an imagination and loose ends allow for it to run rampant.

On-Topic:
If Arthas is in the movie, Hemsworth would be a great Arthas.

None of those pictures on Nikolaj Coster-Waldau's IMDB page really show why he'd make a good Arthas (him dressed as Jaime Lannister). Not sure he'd make a great Arthas, but he'd be a million times better than Hemsworth.